Lord John, a detective novelist and the Marquis of Haslemere's brother, receives word that the stage adaption of one of his stories will not be performed because Roger Odell, a millionaire, has spoken against him. After tracking him down, Lord John joins his foe on an ocean steamer along with Grace Callender, an heiress, and Dr. Rameses, a hypnotist and Egyptian cultist. While the evil Dr. Rameses tries to steal a gold-filled mummy from Maida, Odell's adopted sister, Lord John confronts Odell, who reveals that his anger stems from a disservice that the Marquis once committed against Maida.